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The ChromoTek Spot-Trap® is an affinity matrix for immunoprecipitation of Spot-tagged proteins.
It consists of an anti-Spot-Tag Nanobody/ VHH, which is conjugated to agarose beads, magnetic agarose beads, or solid magnetic particles.


More information about the Spot capture and detection tag can be found here.


Immunoprecipitation (IP)/ Co-IP
IP/ Co-IP for mass spec (MS) analysis
For protein purification use Spot-Cap

When use Spot-Trap? When use Spot-Cap? Click here.

Spot-Tag is an inert 12 amino acid peptide tag with the sequence PDRVRAVSHWSS.

Spot-Trap Agarose
Spot-Trap Magnetic Agarose
Spot-Trap Magnetic Particles M-270
Spot VHH, recombinant binding protein
iST Spot-Trap Kit for IP plus sample preparation for MS

anti-Spot VHH, Spot binding protein, Spot Nanobody, or anti-Spot single domain antibody fragment (sdAb)

Benefit from Spot-Trap for Immunoprecipitation (IP)

  • Reduced background
  • High binding affinity, low dissociation constant KD of 6 nM for Spot fusion proteins
  • Harsh washing conditions
  • High reproducibility
  • Short incubation time of 30-60 minutes
  • Extraordinary low background compared to other affinity resins

Comparison of matrices & properties

We offer Spot-Trap as Agarose, Magnetic Agarose, and Magnetic Particles M-270.

  Spot-Trap Agarose  Spot-Trap Magnetic Agarose  Spot-Trap Magnetic Particles M-270
Low background  +++  ++  ++
Binding capacity  +++  +++  +
Size Spot-tagged protein*   Small to large  Small to large  Small to very large
Bead separation  Centrifugation  Magnetic  Magnetic

* Does depend on protein size and shape, protein multimers, complexes and interaction partners

What Spot-Trap shall I use?

  • Spot-Trap Agarose, when lowest background and high binding capacity IP is needed. 
  • Spot-Trap Magnetic Agarose, when magnetic separation and high binding capacity IP is needed.
  • Spot-Trap Magnetic Beads, when very large proteins/complexes are investigated, and magnetic separation is needed for IP.
  • iST Spot-Trap kit for immunoprecipitation plus sample preparation for mass spectrometry (MS)


Spot-Trap binds to the sequence motif PDRVRAVSHWSS.

Spot-Trap is a very low background affinity reagent. See benchmark of Spot-Trap Agarose and Magnetic Agarose with other suppliers’ capture tools. Immunoprecipitations were conducted from HEK293T cell lysates without Spot-Tag present and normalized for equal binding capacity. The IPs were done according to respective manufacturers’ protocols. It is apparent that Spot-Trap does not only lack heavy and light chain antibody contaminations but also unspecific binding. This makes Spot-Trap a superior affinity capture tool for single band purification of Spot-tagged proteins.

About Spot

ChromoTek’s proprietary and novel Spot-System is the first peptide-tag specific Nanobody for universal capture & detection applications. It comprises Spot-Tag®, an inert 12 amino acid peptide-tag (PDRVRAVSHWSS), which has been affinity optimized, and the universal, rugged Spot-Nanobody that specifically binds to Spot-tagged proteins with high affinity.
Spot-Tag peptide is derived from the protein beta-catenin: its sequence has been optimized for higher affinity binding to the Spot-Tag Nanobody. For further information see here.


Spot-Label samples available

Request a free sample here and test the all-rounder Spot in you experiment.

Download Whitepaper
Order Free Test-Sample
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Only for research applications, not for diagnostic or therapeutic use!